Non Invasive Prenatal Testing, Turning Point in Detection of Down and Other Frequent Trisomies

Abstract

1 Sarem Fertility & Infertility Research Center (SAFIR) & Sarem Cell Research Center (SCRC), Sarem Women’s Hospital, Iran University of Medical Science (IUMS), Tehran, Iran. Background and Aims: Noninvasive prenatal genetic testing (NIPT), which analyzes cell-free fetal DNA circulating in maternal blood, is a new option in the prenatal screening and testing paradigm for trisomy 21 and a few other fetal chromosomal aneuploidies. NIPT technologies have been validated in singleton pregnancies at high risk for trisomy 21 due to advanced maternal age, an abnormal serum screen, personal or family history of aneuploidy, and abnormal ultrasound. The testing is non-invasive, so the pregnancy is not put at risk for miscarriage or other adverse outcomes associated with invasive testing procedures. At least 99% of all pregnancies with trisomy 21 can be detected using this test. However, up to 1 in 100 pregnancies with trisomy 21 will have a normal result and be missed on screening. Conclusion: The International Society of Prenatal Diagnosis (ISPD) and the Iranian Ministry of Health endorse the NIPT method as a suitable screening test for women at high risk for trisomy 21. Positive results should be confirmed by invasive tests. Future advances in NIPT technology promise to expand the range of conditions that can be detected, including single-gene disorders.